LAHORE, Pakistan (CNN) -- The United States has urged Pakistan's President Pervez Musharraf to sever his links with the military and reinstate civilian rule.

"Our hope is that he will restore democracy as quickly as possible," President Bush said Monday after a White House meeting with Turkey's prime minister.

Musharraf imposed emergency rule in Pakistan on Saturday, saying the suspension of his country's constitution was made necessary by the growing threat of terrorism and out-of-control judicial activism.

By imposing a state of emergency, Musharraf suspended Pakistan's constitution and put elections that had been scheduled for January on indefinite hold. Press freedoms have been curbed and independent television stations taken off the air.

Bush said Monday he recognized the threat Musharraf faces from extremists, citing past attempts on Musharraf's life, but said the emergency measures "undermine democracy." Watch Bush's message to Musharraf »

"We expect there to be elections as soon as possible and that the president should remove his military uniform," Bush said.

Musharraf is also Pakistan's military chief. Pakistan is a nuclear power and a key U.S. ally in the war on terror.

Senior U.S. officials said U.S. Ambassador to Pakistan Anne Patterson and other senior ambassadors -- including Britain's -- met with Musharraf on Monday to raise Washington's concerns with the "heavy-handed" measures taken in Lahore, where police, wielding batons, clashed with lawyers and journalists Monday outside the courthouse.

Video showed plainclothes security officials herding protesters onto large buses, sometimes dragging them through the streets, as uniformed officials shot tear gas canisters in an attempt to control the demonstrations.

Don't Miss

The confrontation took place as more than 1,500 lawyers were arrested across the country -- 1,200 in Lahore itself and more than 300 in Faisalabad and Karachi -- with police blocking roads leading to courthouses in major cities.

Senior Pakistani officials said the figure of 1,500 detainees is an underestimate and that several thousand lawyers across the country of 160 million people have been detained. They added that police stations are packed with the detainees, forcing the government to use schools as temporary holding cells.

Political opposition figures have also been rounded up. Qazi Hussain Ahmad, president of the country's largest Islamic party, said he has been placed under house arrest. Ahmad, a prominent opposition leader and head of the Religious Party Alliance, is confined to his home in Lahore.

The Associated Press reported that Pakistan's opposition groups believe about 3,500 people are detained.

Others under arrest include more than 60 members of former Prime Minister Benazir Bhutto's Pakistan People's Party, a senior police official said.

Bhutto's spokesman called Musharraf's declaration an "act of terror" against civil society and predicted it marked "the beginning of the end of Musharraf."

Unlike other opposition leaders, Bhutto remains free and her spokesman denied reports she may have struck a deal with Musharraf. He said Musharraf "would face a severe backlash" if he arrested Bhutto.

Bhutto condemned the arrests of her party members at a news conference Monday in Karachi and said she will head to Islamabad on Wednesday for a meeting of Pakistan's opposition parties.

Your I-Reports

She also called on world leaders to put pressure on the Pakistani president to reinstate the constitution.

Britain called on Pakistan's government to release all political prisoners detained under the emergency. A spokesman for Prime Minister Gordon Brown said Britain is reviewing its aid program to Pakistan, worth $493 million over the next three years.

Pakistani Interior Minister Aftab Ahmed Khan Sherpao said elections would not be held until "things become normal." Watch interior minister discuss the emergency »

While Musharraf said the suspension of the constitution was made necessary by the growing threat of terrorism and out-of-control judicial activism, opponents said Musharraf was trying to avoid a Supreme Court decision expected in the coming days possibly ruling him ineligible for the presidential term he just won.

The United States postponed a Pentagon official's visit to Pakistan this week for a yearly meeting with his Pakistani defense counterpart.

Opposition parties had petitioned the Supreme Court to declare Musharraf ineligible for a third term as president because he remains the head of the country's military. E-mail to a friend

CNN's Elise Labott and Alphonso Van Marsh contributed to this report

Copyright 2007 CNN. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed. Associated Press contributed to this report.